1. Field of the Invention
The present invention relates to a manufacture field of a liquid crystal display, and more particularly to a method of making a filter.
2. Description of the Prior Art
FIG. 1 is a schematic diagram of implementation steps of a filter making method in the prior art, including the following steps: a step S10 providing a transparent substrate; a step S11 forming a light-shielding layer on a surface of the transparent substrate; step S12 patterning the light-shielding layer to form a first groove, a second groove and a third groove therein; a step S13 forming a first color-resisting block on the position of the first groove; and a step S14 orderly forming a second and third color-resisting blocks on the positions of the second and third grooves.
FIGS. 2A-2E show process schematic views of the filter making method in the above prior art.
As shown in FIG. 2A and referring to the step S10, the transparent substrate 200 is provided. The transparent substrate 200 is a support body of a filter, and the material thereof may be, but not limited to, glass.
As shown in FIG. 2B and referring to the step S11, the light-shielding layer 210 is formed on the surface of the transparent substrate 200. The light-shielding layer 210 is made of a black light-shielding material for forming a separate section between the color-resisting blocks having different colors. There is no light passing through the separate section thereby distinguishing the edges between the color-resisting blocks having different colors.
As shown in FIG. 2C and referring to the step S12, the light-shielding layer 210 is patterned to form the first groove 211, the second groove 212 and the third groove 213 therein. This step may adopt a common photo-etching development process to form a predetermined pattern in the light-shielding layer 210. The predetermined pattern should include the first groove 211, the second groove 212 and the third groove 213, which are used to receive the color-resisting blocks having three different colors, such as red, green, and blue, for forming one pixel. Of course, in the application, it may include more groups of grooves for receiving more pixels according to the design demand. The number of the color-resisting blocks of each pixel and the corresponding grooves also may be increased or reduced according to the factual demand.
As shown in FIG. 2D and referring to the steps S13 and S14, the first color-resisting block 231 is formed on the position of the first groove 211, and the second color-resisting block 232 and the third color-resisting block 233 are orderly formed on the positions of the second groove 212 and the third groove 213 according to the method of the step S13. This step may first form a continuous first light-resisting layer (not shown in FIG. 2D), which is used to form the first color-resisting block 231, on the light-shielding layer 210; and then may adopt the common photo-etching development process to remove unnecessary parts and remain the partial first light-resisting layer corresponding to the first groove 211, so that forming the first color-resisting block 231. The methods of forming the second color-resisting block 232 and the third color-resisting block 233 are same as above. The above three color-resisting blocks 231, 232 and 233 may represent the three-color color-resisting blocks of a red resister, a green resister, a blue resister and so on, thereby forming a separate color pixel on the surface of the transparent substrate 200. Of course, the transparent substrate 200 also may further dispose more above three-color color-resisting blocks thereon for producing more pixels. And each pixel also may not be limited to three blocks, for example, may include only one or two color-resisting blocks applied to the gray display. For more advanced design, it cannot exclude the possibilities of adopting the more color-resisting blocks.
The disadvantage of the prior art is that: the chromas of the color blocks are in proportion to its film thickness, namely the chroma is controlled by their film thickness, so the heights of the different color-resisting blocks are determined by the demand for the product chroma. But because the materials of different color blocks are different, that results in the thicknesses of the color-resisting blocks of three colors being different from each other after becoming films and the heights of the three blocks also being different. As shown in FIG. 2D, the height of the first color-resisting block 231 is apparently higher than those of the two other color-resisting blocks. Because of the evenness of inside surfaces of the filter being not good, the abnormity easily occurs during the alignment of liquid crystals and affects the picture-displaying result displayed by the liquid crystal display.
Moreover, in the stacked area between the colorized color-resisting blocks and the remained light-shielding layer, two ends of the three color-resisting blocks 231, 232 and 233 are protruding due to effect of the light-shielding layer, as shown in FIG. 2E, so that resulting in the so-called “ox horn-shaped segment difference” and the evenness of inside surfaces of the filter being not good.